Transmission mechanism.



R. HERMAN. TRANSMISSION mEcHANlSM;- APPLICTI'ON FILED JAN. 9, 4i911.

' Patented Apr. 4, 1916 `2 SHEETS-'SHEET l.

aan,

R. HERMAN. TRANSMISSION MECHANISNI.

APPLICATION FILED IAN. s, 1911.

1, 178,010. Patented Apr. 4,1916.

2 SHEETS-SHEET 2.

a s a 7 Snowdon l como eiybod 3100303 UNITED sTATEs PATENT oEEicE.

REINHOLD HERMAN, F GRAFTON, PENNSYLVANIA.

TRANSMISSION MECHAN ISM.

Specification of Letters Patent.

Application tiled January 9, 1911. Serial N o. 601,758. 7

To all Iu-iom t may concern.'

Be it knownv that I, REINHOLD HERMANLa citizen of the United States of America, residing at Grafton, in the county of Alleghen)7 and yState of Pennsylvania, have invented certain new and useful Improvements in. Transmission Mechanisms, of

which the following is a specification.

My invention relates to improvementsiii transmission mechanism, and has particular relation to mechanism ifor operatively connecting a drive shaft to a driven shaft through speed-changing mechanism.

The present invention is more particularly designed for use in connection with a casing or supporting device disclosed in mv companion application filed January 9, 1911, Serial No. 601,754, but the structure disclosed herein is such as will permit its use independently7 of such casing and in capacities wliere change-speed mechanism as a part of a transmitting mechanism is emplotved.

Among the objects of the present invention are to be found the following: (1) The provision of a differential mechanism carried b v the driven shaft, which mechanism includes a carrier on which the various driven gears for imparting motion to the driven shaft are secured; (2) the provision of a plurality of driven gears carried by the driven shaft with a selecting drive gear loosely mounted on a constantly driven shaft and adapted to be clutched thereto, when the drive gear has been moved into operative relation to the selected driven gear; (3) the provision of a constantly driven shaft carrying a coupling member and also carrying a loosely mounted drive gear adapted to be shifted into and out of en` gagement with the clutching member, and a driven gear mounted on a driven shaft and ixedlv held against axial movement, said driven gear and clutch member being relatively positioned to permit an operative engagement of the drive and driven gears before clutch-engagement of the constantlydriven shaft and the drive gear is had; (4) the provision of drive and driven gear engagement by relative axial movement and so formed and arranged as to provide. for engagement without possibility of stripping the teeth. obviating danger of operators unfamiliar with transmission mechanisms injuring same in manipulation thereof.

To. these and other ends, the nature of which will be readily understood as the invention is hereinafter disclosed, said invention consists in the improved construction and combination of parts hereinafter fullv described, illustrated 'in the accompanying drawings, and particularly pointed out in the appended claims.

In the drawings, in which similar reference characters indicate similar parts in each of the views, Figure 1 is a sectional view taken centrally through the mechanism and showing the shiftable gears inia neutral position. Fig. 2 is an enlarged detail view ofrone of the shiftable members, its shaft and coupling or clutch-member, and the gear driven by said shiftable drive gear, the gears being shown in position just prior to coupling of the drive gear with its shaft. Fig. 3 is a sectional view taken 0n the line 3-3 of Fig. 1. Fig. et is a sectional view taken through the differential mechanism on the line 4-4 of Fig. 1. Fig. 5 is a view somewhat diagrammatic, showing the tooth arrangement of the gears.

In the drawings, 10 designates the drive shaft, having a drive pinion 11 secured thiereon, said pinion being in constant mesh with a bevel gear 12 secured to a shaft 13 mounted in suitable bearings, said shaft 13 being constantly driven from the drive shaft through the pinion 11 and gear l2. The shaft 13 is provided on opposite sides of the gear 12 with coupling or clutch members 14, and 14a, said members each being mounted to rotate with the shaft and having an end configuration adapted to coperate with complemental members carried by shiftable gears presently described. The shaft 13 is also provided adjacent its ends with clutch members 14" and 14 also arranged with an end configuration complemental to coupling faces or members carried by the-shift- 'able gears referred to, the coupling ends of `the members 14 and 14, and 1l and 14, facing each other and spaced apart a distance sufficient to provide for the shifting movements of the shiftable drive gears. 15 and 15a designate the sections of the driven shaft and on which is mounted a gear carrier 1G.

said carrier being formed to support the change-speed driven gears 17, 17a and 1'7", said gears being of different diameter to provide the speed variations. it being understood that the driving of either of said gears causes the driven shaft to be rotated.

Patented Apr.4,1916.

vided with two gear faces 18a and 18b adapt` Loosely mounted on the shaft 13 are the drive gears 18 and 19, the former being proed to coperate respectively with the gears 17 and 17?. The gear 18 is'provided on its opposite ends with coupling orclutch mem bers 2O and 20a, the former' being adapted to coperate with the' clutch member 14h,

and the latter with clutch member 14, suf-A ficient play being provided between the complemental clutch-members to permit the gearl 18 to occupy a neutral position out of engagement with lthe two driven gears with which it is adapted to coperate, and to move axially a distance suliicient to provide a material overlapping ofthe teeth of cooperating gear-faces'prior to the engage- Igient of the complemental coupling mem-y ers.

21 designates a gear in permanent mesh -With the gear 17b,said gear 21 being car-- ried by a stub shaft 22 suitably-supported in bearings 23, said shaft also carrying a driven gear 24 spaced from the gear 21 a distance suilicient to permit the gear 19 tol Ahave a neutral position therebetween, lthe paths of movement of the gear-faces of gears 17" and 24 being lso arranged as topermit the gear 19 to be moved into engage- `ment with either of said gears. -19 is also provided on opposite ends with The gear n and for the same purpose.

Asl shown` in the drawings, the gear teeth ,l of the gears adapted to be engaged during the axial movements of the shifting Adrive gears have their "ends which are Vadapted to be brought into engagement beveled, chamfered'or otherwise formed, to decrease the side face of a tooth and increase the distance between the teeth on thef plane of such side face, thereby permitting of a ready entrance of the teeth to be engaged.

By this construction and arrangement of parts it will be readily seen that owmg to the fact that the shifting gears 18 and 19 are loosely mounted on the constantly drlven shaft 13, the movement of the latter will not positively impart a rotary movement to the gears while the latter are shifted within the limits of their movements when\ uncoupled; therefore, the shifting of the gears 18 and 19, when the driven shaft is at rest, causes the opposing faces of the drive and driven gears to readily enter and engage, the tendency of the drive gearl to rotate with the shaft providing any slight movement of the ydrive gear to insure entrance of the' teeth to be engaged; andv this engagement is also readily had when the driven shaft is in motion, the driven gears while rotating, passingby the opposing teeth of the drive gear to be engaged and permitting the latter tov make entrance therein and be carried thereby irrespective of the constant movement of the shaft on which the drive gears are mounted. As will be readily understood, the movement of the shifting drive gears axially can be had without engagement of the clutching-members, and to,a distance suiicient to provide an overlapping of teeth to any desired extent, preferably an overlap of approximately half of the length of the tooth; obviouslyan overlap of this extent is suiiicient to prevent vany liability ofthe strippingof teeth due to Athe fact that the gear has assumed its relative speed with relation to the engaged gear before the clutch becomes effective. When the drive gear is shifted in the opposite direction, the clutch is uncoupled before the.f gear teeth are wholly disengaged, sothat the drive gear is free to be moved to neutral position without being subjected to the load of theugo drivevshaft 13.

The differential mechanism hereinl disclosed is of a particular construction although. of the general-type of ldifferential gearing. This differential mechanism is preferably formed as follows The gear carrier 16 is formed in two parts indicated as 16a and 16"', the parts 16a having a radial .flange 30r extending from the hub of the part, a circular band-like part 30 extending concentric with the axis of the shaft vand is. of a length sufficient to form a housing for the several gears which act to prdvide theV differential movement, the opposite end of the part 30a having an inwardly-extending lange30b of a radial length less than the similar length of the ange `30, the parts 30, 30a and 30b forming a housing for the differential gears. The flanges 30 and 30b are provided with openings at proper intervals for the passage of bolts 31, each of which act asa support for a differential gear, the bolts 31 being equal in number to the number of rolling gears within the housing, said bolts 31 also projecting through and connecting the gear 17 to the flange 30 and gear 17a to the flange 30", thus connecting said driven gears to the housing and to the supports for rolling gears." As shown in Fig. 1, the gear 17a has a hub-like portion ex- 120 tending inwardly into the space within the' Bange 30", said hub-like portion being mounted on the part 16 of the gear-carrier, said part being secured to said gear 17a by rivets or other suitable fastening device.

Mounted on the driven shaft within the housing are gears 32 and 33, said gears being mounted respectively on the separate parts of the divided shaft. Said gears 32 and 33' are preferably keyed to Atheir re- 13| spective shafts in the manner presently described, and are preferably formed so as to provide an annularspace therebetween on the plane of the gear faces approximately equal to about one-third of the distance be- -tween the flanges 30 and 30". The rolling gears, indicated as 34 are, as heretofore pointed out, mounted on the bolts 31, each ear havin Y an a roximate active len h providing an overlap of the gears of the pair equal to the width'of the space between the gears 32 and 33, this overlap providing the permanent engagement between the gears of each pair. As will be readily understood, this particular arrangement causes one gear of each pair to engage with the fixed gear 32, while the other gear of the pair engages the gear 33, the gears of each pair ehgaging each other, these various engagements and the particular mounting of the supports for the rolling gears (the bolts 31) providing for the required movements of the gears to produce the differential action, it being clear that, by reason of the particular manner in which the parts are secured together,

the flanges 30 and 30", the part 30a, the gear 17a, and the part 16a act to frm a positive connection between the two sections of the driven shaft.

As will be seen, the gears 32 and 33 are keyed to the sections of the driven shaft preferably on opposite sides diametrically of the shaft, the keys being of a length less than the distance between the opposing faces of the gear carrier, thereby providing an annular space therebetween substantially corresponding to the Vdistance between the shaft sections; the keys are also formed with cutout portions which are adapted to receive an annular ring 37 which loosely its the space between the gears 32 and 33, said ring 37 `thus acting to retain the gears spaced apart, and at the same time preventing longitudinal movement of the keys, this latter`- preventing any liability of the keys passing into an overlapping relation, in

operation, and avoiding any liability ofv damaging the structure by the overlapping l of keys.

In assembling the dilerential mechanism, the gear 17 is placed on the carrier 16, and gears 34 are then placed inside of carrier 16 and bolts31 inserted through openings in gears 17 and carrier 16 and also through openings in gears 34 holding the same in posltion. Gears 32 and 33 are then placed on their respective sections of the driven shaft, and section 15 to which gear 32 is attached is entered through opening 16c and through opening in carrier 16 until gear 32 meshes with one half ofthe gears 34; then ring 37 is placed in position on section 15. Shaft 15a carrying gear 33 is then placed through the opening of the part 16" of the carrier which also carries gear 17a and gear 17 b. When this assembly is completed then gear 33 carried by section 15a is entered through the opening 16, and then gear 33 will mesh with the-other half of gears 34. Then bolts 31 are screwed into the openings provided therefor in gear 17a thereby securing the two halves of the carrier intoone unit.

This construction of differential mechanism not only provides foran efficient operation, but the construction is such as to provide for ay ready 'assemblage of parts, a du; rable construction not readily damaged, and a structure which can be easily taken down when necessary in such a manner as to render mistakes in assembling practicallyimpossible. l

' I desire to call attention to the fact that in this system of shifting gears, it is made possible at all times to first engage the gear to be driven without having` to conte-nd with any load other than the weight of the shifting gear itself thereby providing for engagement between the gears without any friction or shock, the shock taking place after the engagement 'of the gears when the clutch movement is being completed and necessarily must be distributed throughout Y the whole transmission mechanism. This particular advantage is additionally derived from the fact that the intermediate shaft 13 is driven at decreased speed relative to the drive shaft, the gea`=r connections between these shafts being of such ratio as to permit the shaft l10, to rotate at high speed without causing the Shaft 13 to run at excessive speed. This particular arrangement becomes of especial advantage in changing speed or picking-up after drifting, the axle causing the gears thereon to be rotating at a speed which more nearly approximates the speed of the shaft 13 than that of the bility of stripping the gears, the slight dif ference in relative movement tending to avoid clashing especially when the teeth are pointed as shown.

While I have herein disclosed one type of structure embodying the general idea contemplated by the present invention, it will 13o' be readily understood that the same may be changed and modified Vwithout departing from the ideapI therefore desire it' to be understood that I reserve the right to make i axis at right angles to the axes of the driven` members, a shiftable gear mounted on the" constantly driven member, ,said -shifltable gear being movable to be driven by or' run free upon said constantly driven member at will, said shiftable gear being movable to engage the gear on said second driven mem- Y ber while the shiftable gear is free to rotate on its member, the shiftable gear having clutch faces and the gear on. the first mentioned driven memberv having clutch faces, bearingssupporting the driven member, and a clutch member engaged directly against one memberv of the bearings and engageable by one of the faces of the shiftable gear.

2. In `change speed mechanism, a drive member, a member driven constantly by said drive member at a relatively reduced speed, meshing gears on the drive 'and driven members, a second driven member, a

gear thereon,"said driven ,members exgtend-A ing in parallelism and the drivemember having itsjjxisl at right angles to the axes of the dr` en members, a 'shiftable gear mounted on the constantly driven member,

said shiftable gear being movable to be driven by or run free .upon said constantly driven memberat will, said shiftablegear being movable to engage the gear on said second driven member while the shiftable,

gear is free to rotate on its member, the Shift'able gear having clutch faces and the gear on the first mentioned driven member having clutch faces, bearings. supporting the driven I nemb'er,` and a clutch member engaged'directly against one member of the bearings and engageable by one of the faces of the shiftable gear, the clutching faces being engageable only when the gears have passed into engagement.

. y 3: In change speed mechanisnn-a drive member, a member" driven constantly by -said driveA member at a relatively reduced speed, a driven member, a gear thereon, said drivenl members extendingv in parallelism and the drive member having its axis at right angles to the axes of the driven members, a shiftable gear mountedon the constantly driven member, said shiftable gear being movablevto .be driven by or run free upon said constantly driven member at will, said shiftable gear being movable to engage the driven member gear while the shiftable gear is free -to rotate on its member, said '.shiftable gear and the member on which it is 'supported carryingeomplemental clutching-faces engageable only after the gears have passed intol engagement, the clutching'- faces passing into contact prior to the completion of the (movement of the gear to its normal vdrive position, said clutching faces lof the shiftable gear being formed integral therewith and the complementary faces being supported directly against a bearing member 'and the gearing on vthe driven member.

In testimony whereof -I afhx my signature in `presence of two witnesses.

. REINHOLD HERMAN.

Witnesses y y A. M. WILSON, Y HORACE G. SErrzi. 

